NavList:
A Community Devoted to the Preservation and Practice of Celestial Navigation and Other Methods of Traditional Wayfinding
Re: no leap second coming in December
From: Frank Reed CT
Date: 2004 Jul 29, 13:57 EDT
From: Frank Reed CT
Date: 2004 Jul 29, 13:57 EDT
Geoffrey K wrote:
>I do know that the large dam/reservoir projects of the first half of the
>20th century contributed significantly to Delta T.
This story was poorly reported in the popular press. The effect of the reservoirs on the Earth's angular momentum is large, but not measurable.
And:
"Perhaps the drying up of the Aral sea and (to a lesser extent) the Dead sea
is cancelling this contribuion...?"
You could work it out. Take the water that has been lost from the Aral Sea and spread it out uniformly over the Earth's surface. What is the change in angular momentum. But while you're thinking about this, consider that the Caspian Sea has been RISING while the Aral Sea has been falling (unrelated causes). By the way, the water loss from the Dead Sea is miniscule compared to other bodies of water worldwide.
Frank R
[X] Mystic, Connecticut
[ ] Chicago, Illinois
>I do know that the large dam/reservoir projects of the first half of the
>20th century contributed significantly to Delta T.
This story was poorly reported in the popular press. The effect of the reservoirs on the Earth's angular momentum is large, but not measurable.
And:
"Perhaps the drying up of the Aral sea and (to a lesser extent) the Dead sea
is cancelling this contribuion...?"
You could work it out. Take the water that has been lost from the Aral Sea and spread it out uniformly over the Earth's surface. What is the change in angular momentum. But while you're thinking about this, consider that the Caspian Sea has been RISING while the Aral Sea has been falling (unrelated causes). By the way, the water loss from the Dead Sea is miniscule compared to other bodies of water worldwide.
Frank R
[X] Mystic, Connecticut
[ ] Chicago, Illinois
